Refrigerant recovery device and method of operation

ABSTRACT

A refrigerant recovery device comprising a pump; a heat rejecting heat exchanger disposed in fluid communication with the pump; a refrigerant storage container disposed in fluid communication with the heat rejecting heat exchanger and the pump; a fluid interface disposed in fluid communication with the pump and configured for fluidly connecting the refrigerant recovery device to a refrigerant containing device; and a plurality of valves disposed in fluid communication with at least one of the pump, the heat rejecting heat exchanger, the refrigerant storage container, or the fluid interface and configurable to establish a first fluid pathway fluidly connecting the refrigerant containing device to the refrigerant storage container, and a second fluid pathway fluidly connecting the heat rejecting heat exchanger to the refrigerant storage container.

CROSS REFERENCE TO A RELATED APPLICATION

The application claims the benefit of U.S. Provisional Application No.63/269,490 filed Mar. 17, 2022, the contents of which are herebyincorporated in their entirety.

BACKGROUND

Exemplary embodiments pertain to the art of recovering refrigerant fromrefrigerant containing devices. More particularly, the presentdisclosure relates to configurations and operations of a refrigerantrecovery device.

Refrigerant containing devices can include air conditioners, heat pumps,condensers, dehumidifiers, refrigerators, freezers, and other vaporcompression driven machines. These devices can include one or moreclosed refrigerant circuits. Evacuation of the refrigerant from the oneor more circuits can be necessary to prevent environmental release whenpart replacement (or refrigerant replacement) is desired. Accordingly,there remains a need in the art for devices capable of evacuatingrefrigerant from refrigerant containing devices at least to support themaintenance and decommissioning activities associated with thesedevices.

BRIEF DESCRIPTION

Disclosed is a refrigerant recovery device comprising a pump; a heatrejecting heat exchanger disposed in fluid communication with the pump;a refrigerant storage container disposed in fluid communication with theheat rejecting heat exchanger and the pump; a fluid interface disposedin fluid communication with the pump and configured for fluidlyconnecting the refrigerant recovery device to a refrigerant containingdevice; and a plurality of valves disposed in fluid communication withat least one of the pump, the heat rejecting heat exchanger, therefrigerant storage container, or the fluid interface and configurableto establish a first fluid pathway fluidly connecting the refrigerantcontaining device to the refrigerant storage container, and a secondfluid pathway fluidly connecting the heat rejecting heat exchanger tothe refrigerant storage container.

In accordance with additional or alternative embodiments, wherein thefirst fluid pathway extends from the refrigerant containing device,through the fluid interface, the pump and the heat rejecting heatexchanger, and into the refrigerant storage container, and the secondfluid pathway extends from the heat rejecting heat exchanger through thepump and into the refrigerant storage container.

In accordance with additional or alternative embodiments, wherein thesecond fluid pathway is dead ended upstream of the heat rejecting heatexchanger.

In accordance with additional or alternative embodiments, wherein thefirst fluid pathway is configured such that during operation the pumppressurizes the heat rejecting heat exchanger as it pushes a refrigerantflow therethrough and the second fluid pathway is configured such thatthe pump depressurizes the heat rejecting heat exchanger as it draws therefrigerant flow into the refrigerant storage container.

In accordance with additional or alternative embodiments, furthercomprising a second pump, and wherein the second pump is disposed in thesecond fluid pathway disposed in fluid communication with, andinterposed between, the heat rejecting heat exchanger and therefrigerant storage container.

In accordance with additional or alternative embodiments, furthercomprising an oil separator disposed in the first fluid pathway in fluidcommunication with, and interposed between, the pump and the heatrejecting heat exchanger.

In accordance with additional or alternative embodiments, furthercomprising an oil separator disposed in the first fluid pathway.

In accordance with additional or alternative embodiments, furthercomprising a pressure relief device disposed in fluid communication withthe heat rejecting heat exchanger.

In accordance with additional or alternative embodiments, wherein therefrigerant containing device contains a refrigerant to be recoveredcomprising a refrigerant having a 100-year global warming potentialrelative to a carbon dioxide reference gas of less than or equal to2000.

In accordance with additional or alternative embodiments, wherein theheat rejecting heat exchanger comprises a heat conducting coil disposedin thermal communication with a consumable heat sink.

In accordance with additional or alternative embodiments, furthercomprising a controller in operable communication with the pump and theplurality of valves and configured to change an operating state of oneor more valves of the plurality of valves to establish one of the firstfluid pathway and the second fluid pathway based on one or more feedbackconditions.

In accordance with additional or alternative embodiments, wherein theone or more feedback conditions comprise at least one of a pressure ofthe refrigerant containing device, a pressure of the heat rejecting heatexchanger, a pressure of the refrigerant storage container, a pressureof the oil separator, a temperature of the refrigerant containingdevice, a temperature of the heat rejecting heat exchanger, atemperature of the refrigerant storage container, a temperature of theoil separator, or an elapsed time.

In accordance with additional or alternative embodiments, wherein theestablishment of the first fluid pathway is mutually exclusive with theestablishment of the second fluid pathway.

In accordance with additional or alternative embodiments, furthercomprising a movable structure configured to hold one or more of thefluid interface, the pump, the heat rejecting heat exchanger, therefrigerant storage container, or the plurality of valves.

Further disclosed is a method of removing a refrigerant from arefrigerant containing device comprising pumping the refrigerant along afirst fluid pathway from the refrigerant containing device through aheat rejecting heat exchanger and into a refrigerant storage containeruntil an initial pull-down threshold condition is satisfied; cooling therefrigerant as it passes through the heat rejecting heat exchanger; andpumping the refrigerant along a second fluid pathway from the heatrejecting heat exchanger to the refrigerant storage container until afinal pull-down threshold condition is satisfied.

In accordance with additional or alternative embodiments, wherein theinitial pull-down threshold condition comprises reaching one or more ofa predetermined pressure condition within the refrigerant containingdevice, a predetermined temperature condition within the refrigerantcontaining device, a predetermined pressure condition within the heatrejecting heat exchanger, a predetermined temperature condition withinthe heat rejecting heat exchanger, a predetermined pressure conditionwithin the refrigerant storage container, a predetermined temperaturecondition within the refrigerant storage container, or a predeterminedinitial pull-down time duration.

In accordance with additional or alternative embodiments, wherein thefinal pull-down threshold condition comprises reaching one or more of apredetermined pressure condition within the heat rejecting heatexchanger, a predetermined temperature condition within the heatrejecting heat exchanger, a predetermined pressure condition within therefrigerant storage container, a predetermined temperature conditionwithin the refrigerant storage container, or a predetermined secondpull-down time duration.

In accordance with additional or alternative embodiments, furthercomprising at least partially obstructing the second fluid pathway whilerefrigerant is pumped along the first fluid pathway; and at leastpartially obstructing the first fluid pathway while refrigerant ispumped along the second fluid pathway.

In accordance with additional or alternative embodiments, furthercomprising pressurizing the heat rejecting heat exchanger when therefrigerant is pumped along the first fluid pathway and depressurizingthe heat rejecting heat exchanger when the refrigerant is pumped alongthe second fluid pathway.

In accordance with additional or alternative embodiments, furthercomprising providing a refrigerant removal device comprising a pump, theheat rejecting heat exchanger and the refrigerant storage containerdisposed in configurable fluid communication, wherein the refrigerantremoval device is configurable between at least a first configurationestablishing the first fluid pathway and a second configurationestablishing the second fluid pathway; configuring the refrigerantremoval device in the first configuration; fluidly connecting therefrigerant containing device to the refrigerant removal device; pumpingthe refrigerant with the pump along the first fluid pathway while atleast partially obstructing the second fluid pathway, cooling therefrigerant in the heat rejecting heat exchanger before it enters therefrigerant storage container; receiving the refrigerant in therefrigerant storage container; and pumping the refrigerant with the pumpalong the second fluid pathway while at least partially obstructing thefirst fluid pathway.

Technical effects of embodiments of the present disclosure includeestablishing an improved refrigerant evacuation device and operationalmethods for removing refrigerant from refrigerant containing devices.The improved device and evacuation methods disclosed herein are capableof achieving very high refrigerant recovery from refrigerant containingdevices, e.g., removal of up to 99.0 weight % of refrigerant from arefrigerant containing device. Such removal extent is consideredsufficient to inert the device when it has previously contained aflammable refrigerant.

The foregoing features and elements may be combined in variouscombinations without exclusivity, unless expressly indicated otherwise.These features and elements as well as the operation thereof will becomemore apparent in light of the following description and the accompanyingdrawings. It should be understood, however, that the followingdescription and drawings are intended to be illustrative and explanatoryin nature and non-limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way.With reference to the accompanying drawings, like elements are numberedalike:

FIG. 1 is a schematic illustration of an exemplary refrigerant recoverydevice having bi-directional valves during initial pull-down inaccordance with one or more embodiments of the disclosure.

FIG. 2 is a schematic illustration of an exemplary refrigerant recoverydevice having bi-directional valves during final pull-down in accordancewith one or more embodiments of the disclosure.

FIG. 3 is a schematic illustration of an exemplary refrigerant recoverydevice having three-way valves during initial pull-down in accordancewith one or more embodiments of the disclosure.

FIG. 4 is a schematic illustration of an exemplary refrigerant recoverydevice having three-way valves during final pull-down in accordance withone or more embodiments of the disclosure.

FIG. 5 is a schematic illustration of an exemplary refrigerant recoverydevice having two pumps during initial pull-down in accordance with oneor more embodiments of the disclosure.

FIG. 6 is a schematic illustration of an exemplary refrigerant recoverydevice having two pumps during final pull-down in accordance with one ormore embodiments of the disclosure.

FIG. 7 is a schematic illustration of an exemplary refrigerant recoverymethod in accordance with one or more embodiments of the disclosure.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosedapparatus and method are presented herein by way of exemplification andnot limitation with reference to the Figures.

FIGS. 1-6 are schematic illustrations of a refrigerant recovery device100 including a pump 40, a heat rejecting heat exchanger 60, and arefrigerant storage container 80 disposed in fluid communication withone another. The refrigerant recovery device 100 can include a fluidinterface 22 for connecting the refrigerant recovery device 100 to arefrigerant containing device 20. The refrigerant recovery device 100can include a plurality of valves disposed in fluid communication withat least one of the pump 40, the heat rejecting heat exchanger 60, therefrigerant storage container 80, or the fluid interface 22 fordirecting a refrigerant from the refrigerant containing device 20 to therefrigerant storage device 80. The plurality of valves can beconfigurable to establish a first fluid pathway 11 (shown with a thickerline in FIGS. 1, 3, and 5 ) fluidly connecting the refrigerantcontaining device 20 to the refrigerant storage device 80 and a secondfluid pathway 12 (shown with a thicker line in FIGS. 2, 4, and 6 )fluidly connecting the heat rejecting heat exchanger 60 to therefrigerant storage device 80. In the figures, for illustrativepurposes, grayed out reference block indicates a closed valve, and aungrayed reference block indicates an open valve. Further, in FIGS. 3-4, a closed valve pathway is indicated by a solid black triangle and anopen valve pathway is indicated by a white triangle.

The first fluid pathway 11 can originate at the refrigerant containingdevice 20 and terminate at the refrigerant storage device 80. Forexample, the fluid interface 22 can fluidly connect the refrigerantcontaining device 20 to the refrigerant recovery device 100 and theplurality of valves can be configured to establish the first fluidpathway 11 from the refrigerant containing device 20 to the refrigerantstorage device 80. Where the first fluid pathway 11 extends from therefrigerant containing device 20, through the fluid interface 22, thepump 40, and the heat rejecting heat exchanger 60, and into therefrigerant storage container 80. Further, as in FIG. 1 , the pluralityof valves can be configured in a first position where interface valve61, heat exchanger hot side inlet valve 62, and heat exchanger hot sideoutlet valve 63 are set in an open position and heat exchanger bypassvalve 64 and recycle valve 65 are set in a closed position. In thisconfiguration, the refrigerant containing device 20 can be dead ended(e.g., sealed except for an outlet) such that the pump 40 can beoperated to depressurize the refrigerant containing device 20 by drawingrefrigerant from the refrigerant containing device 20 and push itthrough the hot side of the heat rejecting heat exchanger 60 and intothe refrigerant storage container 80. The operation of the pump 40 inthis configuration can be referred to as an initial pull-down, whererefrigerant from the refrigerant containing device 20 is initiallyremoved until an initial pull-down threshold condition is satisfied.

The initial pull-down threshold condition can include reaching one ormore of a predetermined pressure condition anywhere in the first fluidpathway 11, or a predetermined temperature condition anywhere along thefirst fluid pathway 11. For example, the initial pull-down thresholdcondition can include reaching a predetermined pressure condition withinthe refrigerant containing device 20, a predetermined temperaturecondition within the refrigerant containing device 20, a predeterminedpressure condition within the pump 40, a predetermined temperaturecondition within the pump 40, a predetermined pressure condition withinthe heat rejecting heat exchanger 60, a predetermined temperaturecondition within the heat rejecting heat exchanger 60, a predeterminedpressure condition within the refrigerant storage container 80, or apredetermined temperature condition within the refrigerant storagecontainer 80, or a predetermined initial pull-down time duration. In anexample, the initial pull-down threshold condition can include reachingless than or equal to about 3 pounds per square inch gauge pressure(psi(g)) within the refrigerant containing device 20, such as less thanor equal to about 2.5 psi(g), or about 2.0 psi(g), or about 1.5 psi(g),or about 1.0 psi(g), or about 0.5 psi(g) or about 0 psi(g). The initialpull-down threshold condition can include a negative gauge pressure(vacuum condition) but doing so can result in air ingress into therefrigerant containing device 20 if there are any air leak paths.

The second fluid pathway 12 can originate at the heat rejecting heatexchanger 60 and terminate at the refrigerant storage container 80. Forexample, the plurality of valves can be configured to establish thesecond fluid pathway 12 from the heat rejecting heat exchanger 60 to therefrigerant storage device 80. Where the second fluid pathway 12 extendsfrom the heat rejecting heat exchanger 60 through the pump 40 and intothe refrigerant storage container 80. Further, as in FIG. 2 , theplurality of valves can be configured in a second position whereinterface valve 61, heat exchanger hot side inlet valve 62, and heatexchanger hot side outlet valve 63 are set in a closed position and heatexchanger bypass valve 64 and recycle valve 65 are set in an openposition. The second position of the valves can be the opposite of thefirst position such that establishment of the first fluid pathway 11 canbe mutually exclusive with the establishment of the second fluid pathway12. In this configuration, the heat rejecting heat exchanger 60 can bedead ended (e.g., sealed except for an outlet) such that the pump 40 canbe operated to depressurize the heat rejecting heat exchanger 60 bydrawing refrigerant from the heat rejecting heat exchanger 60 and pushit into the refrigerant storage container 80. In this way, the firstfluid pathway 11 can be configured such that during operation the pump40 pressurizes the heat rejecting heat exchanger 60 as it pushes arefrigerant flow therethrough and the second fluid pathway 12 isconfigured such that the pump 40 depressurizes the heat rejecting heatexchanger 60 as it draws the refrigerant flow into the refrigerantstorage container 80. The operation of the refrigerant removal device100 in this configuration (e.g., where the plurality of valves aredisposed in their second position) can be referred to as a finalpull-down, where refrigerant from the heat rejecting heat exchanger 60is removed by the action of the pump 40 until a final pull-downthreshold condition is satisfied.

The final pull-down threshold condition can include reaching one or moreof a predetermined pressure condition anywhere in the second fluidpathway 12, or a predetermined temperature condition anywhere along thesecond fluid pathway 12. For example, the final pull-down thresholdcondition can include reaching one or more of a predetermined pressurecondition within the heat rejecting heat exchanger 60, a predeterminedtemperature condition within the heat rejecting heat exchanger 60, apredetermined pressure condition within the pump 40, a predeterminedtemperature condition within the pump 40, a predetermined pressurecondition within the refrigerant storage container 80, a predeterminedtemperature condition within the refrigerant storage container 80, or apredetermined final pull-down time duration. In an example, the finalpull-down threshold condition can include reaching less than or equal toabout 3 pounds per square inch gauge pressure (psi(g)) within the heatrejecting heat exchanger 60, such as less than or equal to about 2.5psi(g), or about 2.0 psi(g), or about 1.5 psi(g), or about 1.0 psi(g),or about 0.5 psi(g) or about 0 psi(g). The final pull-down thresholdcondition can include a negative gauge pressure (vacuum condition) butdoing so can result in air ingress into the heat rejecting heatexchanger 60 if there are any air leak paths.

The first fluid pathway 11 and the second fluid pathway 12 can eachinclude a plurality of conduits disposed between and fluidly connectingone or more of the fluid interface 22, the pump 40, the heat rejectingheat exchanger 60, the refrigerant storage container 80, the refrigerantcontaining device 20, and the plurality of valves into the pathway. Theconduits can be made of any material suitable for conveying refrigerante.g., including a low global warming potential refrigerants. Suchmaterials can include polymers, such as polypropylene, polyphthalamide,acetal, phenolic, polyvinylidene fluoride, polycarbonate, polyethyleneterephthalate, polyetherimide, polyimides, liquid crystal polymer,polyamide, and the like, and metals, such as aluminum, aluminum alloys,copper, copper alloys, iron, iron alloys, lead, lead alloys, tin, tinalloys, zinc, zinc alloys, or combinations thereof.

The fluid interface 22 can be disposed in fluid communication with thepump 40 and can be configured for fluidly connecting the refrigerantrecovery device 100 to the refrigerant containing device 20. Forexample, the fluid interface 22 can include any suitable connector typefor fluidly connecting to a refrigerant containing device 20 such as acompression fitting, swage fitting, threaded connector, or the like forfastening to a corresponding fitting of the refrigerant containingdevice 20.

An interface valve 61 can be fluidly interposed between the pump 40 andthe fluid interface 22. The interface valve 61 can be used to allow, orprevent, refrigerant flow from the refrigerant containing device 20during operation of the pump 40. For example, during the initialpull-down the interface valve 61 can be configured in an open positionto allow refrigerant to be evacuated from the refrigerant containingdevice 20. During the final pull-down the interface valve 61 can beconfigured in a closed position to prevent refrigerant from flowinginto, or out of, the refrigerant containing device 20 or creating avacuum therein.

The interface valve 61 can serve as a shutoff valve when connecting anddisconnecting the refrigerant recovery device 100 to the refrigerantcontaining device 20. For example, while the fluid interface 22 isconnected to the refrigerant containing device 20 the interface valve 61can be closed to prevent refrigerant from entering the refrigerantremoval device 100 prematurely. Similarly, while the fluid interface 22is disconnected from the refrigerant containing device 20 the interfacevalve 61 can be closed to prevent refrigerant from escaping therefrigerant recovery device 100.

The plurality of valves can include two-way valves or three-way valves(as shown in FIG. 3-4 ). When one or more three-way valves are used, oneor more of the fluid interface valve 61, the heat exchanger hot sideinlet valve 62, the heat exchanger hot side outlet valve 63, the heatexchanger bypass valve 64, and the recycle valve 65 may become optionalas the one or more three-way valves may assume their function(s). Forexample, as in FIGS. 3-4 , a first three-way valve 71 and a secondthree-way valve 72 cooperate to eliminate the fluid interface valve 61,the heat exchanger hot side inlet valve 62, the heat exchanger bypassvalve 64, and the recycle valve 65.

When the first three-way valve 71 is used, an optional flow controldevice 73 can be disposed in the second fluid pathway 12. For example, aflow control device 73, such as an orifice, flow control valve, or thelike, can be disposed upstream of the pump 40 inlet, e.g., interposedbetween the heat exchanger 60 and the pump 40 as in FIGS. 4-5 . Thisoptional flow control device 73 can be used to reduce the pressure offluid flowing from the heat exchanger 60 during the final pull-down andcan be set to minimize liquid ingestion into the pump 40. Furthermore,the flow control device 73 can be configured in operable communicationwith the controller 50 and can be configured to adjust an opening amountof the flow control device 73 in response to a condition measured alongthe second fluid pathway 12, such as fluid temperature at the inlet tothe pump 40, temperature at the flow control device 73, temperature ofthe heat exchanger 60 outlet, temperature of the heat exchanger 60inlet, or the like.

Referring to FIGS. 5-6 , the refrigerant recovery device 100 can includean optional second pump 42. The second pump 42 can replace one or moreof the plurality of valves to achieve the same overall function of therefrigerant recovery device 100. For example, the second pump 42 can bedisposed in the second fluid pathway 12 in fluid communication with, andinterposed between, the heat rejecting heat exchanger 60 and therefrigerant storage container 80. The second pump 42 can be fluidlydisconnected from the first fluid pathway 11 while refrigerant is pumpedalong the first fluid pathway 11 during the initial pump down as in FIG.5 and can be fluidly connected to the heat rejecting heat exchanger 60(e.g., via inlet valve 67 and/or outlet valve 69) to establish thesecond fluid pathway 12 during the final pull-down. For example, inletvalve 67 and outlet valve 69 could be replaced with sealable accessports (e.g., quick disconnect fittings) such that the second pump 42 canbe fluidly disconnected during the initial pump down and fluidlyreconnected during the final pump down. When the second pump 42 is used,an optional flow control device 73 can be disposed in the second fluidpathway 12. For example, a flow control device 73, such as an orifice,flow control valve, or the like, can be disposed upstream of the secondpump 42 inlet, e.g., interposed between the heat exchanger 60 and thesecond pump 42 as in FIGS. 5-6 . This optional flow control device 73can be used to reduce the pressure of fluid flowing from the heatexchanger 60 during the final pull-down and can be set to minimizeliquid ingestion into the second pump 42. Furthermore, the flow controldevice 73 can be configured in operable communication with thecontroller 50 and can be configured to adjust an opening amount of theflow control device 73 in response to a condition measured along thesecond fluid pathway 12, such as fluid temperature at the inlet to thesecond pump 42, fluid temperature at the flow control device 73, fluidtemperature of the heat exchanger 60 outlet, fluid temperature of theheat exchanger 60 inlet, or the like.

During the final pull-down the heat exchanger hot side inlet valve 62,or equivalent three-way valve (e.g., first three-way valve 71), can beclosed. In this case, the downstream heat rejecting heat exchanger 60 issaid to be dead ended because there is only a fluid outlet connectedthereto. When refrigerant is sucked from the heat rejecting heatexchanger 60 in this condition (e.g., with pump 40 or second pump 42),the pressure inside the heat rejecting heat exchanger 60 decreasestoward a vacuum condition.

Optionally, the refrigerant recovery device 100 can include an oilseparator 90. The optional oil separator 90 can be disposed anywhere inthe first fluid pathway 11 or the second fluid pathway 12. For example,the oil separator 90 can be disposed upstream of the heat rejecting heatexchanger 60 to reduce the presence of oil in the heat rejecting heatexchanger 60. Furthermore, the optional oil separator 90 can beinterposed between the pump 40 and the heat rejecting heat exchanger 60,such as between the heat exchanger hot side inlet valve 62 and the heatrejecting heat exchanger 60.

Optionally, the refrigerant recovery device 100 can include a pressurerelief valve 91 for relieving pressure within the refrigerant recoverydevice 100 in the event that pressure builds beyond a safe level. Theoptional pressure relief valve 91 can be disposed anywhere in the firstfluid pathway 11 or the second fluid pathway 12 and can be configured torelease pressure from either pathway. For example, the optional pressurerelief valve can be disposed in fluid communication with the heatrejecting heat exchanger 60, such as downstream of the heat rejectingheat exchanger 60. The pressure relief device 91 can be configured torelease pressure at a predetermined high-pressure value to avoidover-pressurizing other components of the refrigerant recovery device100 (e.g., valve, fluid conduits, the heat rejecting heat exchanger 60,the refrigerant storage container 80, or the like). In an example, thepressure relief valve 91 can be set to relieve pressure it is exposed toa pressure differential of about 30 psi(g) or more.

The refrigerant containing device 20 can include any device having arefrigerant circuit such as including air conditioning systems, heatpump systems, refrigeration systems, or the like. The refrigerantrecovery device 100 can be configured for operation with a refrigerantcontaining device 20 containing any type of refrigerant. For example,the refrigerant of the refrigerant containing device 20 can include alow global warming potential refrigerant, such as a refrigerant having a100-year global warming potential relative to a carbon dioxide referencegas of less than or equal to 3000, or less than or equal to 2000, orless than or equal to 1000, or equal to or less than 500. Somenone-limiting examples of refrigerants that can be recovered using thedisclosed refrigerant recovery device 100 include R32, R410A, R454B,R466A, R454C, DR4, DR930, and the like.

When flammable refrigerants are recovered with the refrigerant recoverydevice 100 the components of the device, including the pump 40 (andoptional pump 42) and motor(s) associated therewith, can be selected tomeet National Electric Code (NEC) Class I Division II standards. Thesestandards define a Class I location as a location containing flammablegases or vapors sufficient to pose risk of explosion or ignition. Whilethe designation of Division II indicates that the flammable gases orvapors are only present during abnormal conditions, e.g., failureconditions. Accordingly, the refrigerant recovery device 100 can includenon-arcing and non-sparking brushless DC motors suitable for operationin environments designated as Class I and Division II by the NEC.

The heat rejecting heat exchanger 60 can include any suitable heattransfer device for removing heat from a refrigerant stream. Forexample, the heat rejecting heat exchanger 60 can include a plate ortube style heat exchanger having a high surface area section that can bedisposed in thermal communication with a coolant. The coolant caninclude a fluid coolant that is moved through the heat rejecting heatexchanger 60 (e.g., glycol, air, or the like) or can include aconsumable heat sink material, such as ice, an ice and water mixture,dry ice, or the like, that is placed in thermal communication with theheat rejecting heat exchanger 60. For example, the heat rejecting heatexchanger 60 can include a coil of metal conduit (e.g., copper coil)disposed within an insulated housing (e.g., a cooler) suitable forholding a consumable heat sink material. The heat sink material can beplaced inside the housing in thermal communication with the coil ofmetal conduit. In this way, the heat rejecting heat exchanger 60 can bekept at a relatively constant temperature (e.g., the solid-liquidtransition temperature of the solid coolant such as ice, the sublimationtemperature of solid carbon dioxide, or the like) during the operationof the refrigerant recovery device 100.

The use of a consumable heat sink material in the heat rejecting heatexchanger 60 can allow service persons to use readily availablematerials (e.g., bagged ice) to execute refrigerant recovery in thefield. Furthermore, use of the consumable heat sink material caneliminate the need for noisy condenser fans and/or plumbing coolantsupply/return lines to the heat rejecting heat exchanger 60, therebyimproving the portability, performance, and convenience of therefrigerant recovery device 100 making it suitable for field servicepersonnel.

Accordingly, the refrigerant recovery device 100 can be configured intoa movable device for use in servicing refrigerant containing equipmentin the field. For example, the refrigerant recovery device 100 caninclude a movable structure (e.g., frame, housing, and the like) forsupporting components of the refrigerant recovery device 100. In thisway, the movable frame can be configured to hold one or more of thefluid interface 22, the pump 40, the heat rejecting heat exchanger 60,the refrigerant storage container 80, one or more valves of theplurality of valves (e.g., 61, 62, 63, 64, 65, 67, 69, 71, or 72), oneor more conduits of the plurality of conduits, an optional controller50, the optional oil separator 90, or the optional pressure relief valve91. The movable structure can include a plurality of wheels fortransporting the refrigerant recovery device 100 to and from a work areato perform refrigerant recovery operations. For example, the refrigerantrecovery device 100 can include a movable structure frame for securingcomponents of the refrigerant recovery device 100. The movable structurecan be disposed in operable communication with a plurality of wheels formoving the refrigerant recovery device 100, such as wheeled cart holdingcomponents, or the likes. Further the refrigerant recovery device 100can include a housing to enclose the components of the refrigerantrecovery device 100 such as to protect them from damage during storage,set up, or operation.

Referring to FIG. 7 , methods 200 of operating the refrigerant recoverydevice 100 can include an initial pull-down 210, a final pull-down 240,and a transition therebetween 220. These methods of operating therefrigerant recovery device 100 can be performed manually orautomatically with the optional controller 50. For example, whenconfigured for manual operation the plurality of valves can include handvalves (e.g., quarter turn ball valves, of the like), the pump caninclude a manual start switch, and manually readable pressure and/ortemperature gauges can be applied at points along the first fluidpathway 11 and/or second fluid pathway 12 (e.g., at the refrigerantcontaining device 20, the heat rejecting heat exchanger 60, therefrigerant storage container 80, and the like) to feedback conditionsto the operator.

The initial pull-down 210 can include fluidly connecting the refrigerantremoval device 100 to the refrigerant containing device 20, such as byconnecting the fluid interface 22 to an outlet port of the refrigerantcontaining device 20. In addition, the initial pull-down can includepositioning the plurality of valves in the first position to establishthe first fluid pathway 11 originating at the refrigerant containingdevice 20 and terminating at the refrigerant storage container 80. Oncethe plurality of valves are positioned and the refrigerant containingdevice 20 is fluidly connected to the refrigerant storage container 80the initial pull-down can begin. The initial pull-down can includepumping the refrigerant along the first fluid pathway 11 from therefrigerant containing device 20 through the heat rejecting heatexchanger 60 and into the refrigerant storage container 80 until theinitial pull-down threshold condition is satisfied. During this initialpull-down pumping, the refrigerant can be pushed through the heatrejecting heat exchanger 60 by the pump 40 thereby pressuring the heatrejecting heat exchanger 60 and cooling the refrigerant as it passestherethrough. Furthermore, the positioning of the plurality of valve inthe first position can include at least partially obstructing the secondfluid pathway 12 while refrigerant is pumped along the first fluidpathway 11.

The methods 200 of the refrigerant recovery device 100 can include atransition 220 between the initial pull-down 210 and the final pull-down240. This transition 220 can include satisfying any one or more of thepreviously mentioned initial pull-down threshold conditions, includingholding for a pre-determined time duration before transitioningoperational mode to the final pull-down 240.

The cooling operation during pull-down can reduce the refrigerantpressure and can aide in evacuating the refrigerant containing device 20by keeping the refrigerant in the storage container 80 relatively coldand at a corresponding low pressure. For example, in reclaimingrefrigerant from the refrigerant containing device 20 having 20 pounds(lbs.) of refrigerant, the initial pull-down described herein can removeall but about 0.2 lbs. of refrigerant for a removal efficiency of about99.0%. However, the initial pull-down will leave refrigerant in therefrigerant removal device 100, e.g., within the heat rejecting heatexchanger 60. Following the initial pull-down, the final pull-down 240can be performed to evacuate the heat rejecting heat exchanger 60 tonear completion.

The final pull-down 240 can include positioning the plurality of valvesin the second position to establish the second fluid pathway 12originating at the heat rejecting heat exchanger 60 and terminating atthe refrigerant storage container 80. Once the plurality of valves arepositioned, the final pull-down 240 can begin. The final pull-down 240can include pumping the refrigerant along the second fluid pathway 12from the heat rejecting heat exchanger 60 to the refrigerant storagecontainer 80 until the final pull-down threshold condition is satisfied.During this final pull-down pumping, the refrigerant can be drawn fromthe heat rejecting heat exchanger 60 thereby depressurizing the heatrejecting heat exchanger 60 as it is evacuated. Furthermore, thepositioning of the plurality of valve in the second position can includeat least partially obstructing the first fluid pathway 11 whilerefrigerant is pumped along the second fluid pathway 12. The refrigerantcan continue to cool during this pumping while it is in thermalcommunication with the heat rejecting heat exchanger 60. The coolingoperation reduces the refrigerant pressure and can aide in evacuatingthe heat rejecting heat exchanger 60 by keeping the refrigerant in thestorage container 80 relatively cold and at a corresponding lowpressure.

The method can include fluidly disconnecting the refrigerant removaldevice 100 from the refrigerant containing device 20, such as bydisconnecting the fluid interface 22 from the outlet port of therefrigerant containing device 20. Once the initial pull-down is completeand the plurality of valves are set in their second position, therefrigerant removal device 100 can be disconnected from the refrigerantcontaining device 20 without affecting the refrigerant recovery.

Optionally, the refrigerant recovery device 100 can include a controller50 for controlling the operation of the device during use. Thecontroller 50 can be implemented using a field programmable gate array(FPGA), central processing unit (CPU), application specific integratedcircuits (ASIC), or the like. As indicated by the dashed lines in theFigures, the controller 50 can be configured in operable communicationwith the pump 40, one or more valves of the plurality of valves, thesecond pump 42 (when included), one or more temperature sensors disposedalong the first fluid pathway 11 (e.g., measuring the temperature withinthe refrigerant containing device 20, the pump 40, the heat rejectingheat exchanger 60, the storage container 80, at the fluid interface 22,or the like), one or more pressure sensors disposed along the firstfluid pathway 11 (e.g., measuring the pressure within the refrigerantcontaining device 20, the pump 40, the heat rejecting heat exchanger 60,the storage container 80, at the fluid interface 22, or the like), oneor more temperature sensors disposed along the second fluid pathway 12(e.g., measuring the temperature within the pump 40, the heat rejectingheat exchanger 60, the storage container 80, or the like), one or morepressure sensors disposed along the second fluid pathway 12 (e.g.,measuring the pressure within the pump 40, the heat rejecting heatexchanger 60, the storage container 80, or the like). For simplicity inillustration, pressure and temperature sensors are not shown in thecorresponding drawings.

The controller 50 can be configured to perform one or more refrigerantrecovery methods of the refrigerant recovery device 100. For example,the controller 50 can be disposed in operable communication with thepump 40 and the plurality of valves and configured to change anoperating state of one or more valves of the plurality of valves toestablish one of the first fluid pathway 11 and the second fluid pathway12 based on one or more feedback conditions from the refrigerantrecovery device 100. These feedback conditions can include any of thepreviously mentioned initial pull-down threshold conditions or finalpull-down threshold conditions and can be used (e.g., by an operator orby the controller 50) to change the operating mode of the refrigerantrecovery device 100 (e.g., from an initial pull-down to a finalpull-down, or from a final pull-down to an off mode).

The term “about” is intended to include the degree of error associatedwith measurement of the particular quantity based upon the equipmentavailable at the time of filing the application.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the presentdisclosure. As used herein, the singular forms “a”, “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, integers, steps, operations,element components, and/or groups thereof.

While the present disclosure has been described with reference to anexemplary embodiment or embodiments, it will be understood by thoseskilled in the art that various changes may be made and equivalents maybe substituted for elements thereof without departing from the scope ofthe present disclosure. In addition, many modifications may be made toadapt a particular situation or material to the teachings of the presentdisclosure without departing from the essential scope thereof.Therefore, it is intended that the present disclosure not be limited tothe particular embodiment disclosed as the best mode contemplated forcarrying out this present disclosure, but that the present disclosurewill include all embodiments falling within the scope of the claims.

What is claimed is:
 1. A refrigerant recovery device comprising: a pump;a heat rejecting heat exchanger disposed in fluid communication with thepump; a refrigerant storage container disposed in fluid communicationwith the heat rejecting heat exchanger and the pump; a fluid interfacedisposed in fluid communication with the pump and configured for fluidlyconnecting the refrigerant recovery device to a refrigerant containingdevice; and a plurality of valves disposed in fluid communication withat least one of the pump, the heat rejecting heat exchanger, therefrigerant storage container, or the fluid interface and configurableto establish a first fluid pathway fluidly connecting the refrigerantcontaining device to the refrigerant storage container, and a secondfluid pathway fluidly connecting the heat rejecting heat exchanger tothe refrigerant storage container.
 2. The refrigerant recovery device ofclaim 1, wherein the first fluid pathway extends from the refrigerantcontaining device, through the fluid interface, the pump and the heatrejecting heat exchanger, and into the refrigerant storage container,and the second fluid pathway extends from the heat rejecting heatexchanger through the pump and into the refrigerant storage container.3. The refrigerant recovery device of claim 1, wherein the second fluidpathway is dead ended upstream of the heat rejecting heat exchanger. 4.The refrigerant recovery device of claim 1, wherein the first fluidpathway is configured such that during operation the pump pressurizesthe heat rejecting heat exchanger as it pushes a refrigerant flowtherethrough and the second fluid pathway is configured such that thepump depressurizes the heat rejecting heat exchanger as it draws therefrigerant flow into the refrigerant storage container.
 5. Therefrigerant recovery device of claim 1, further comprising a secondpump, and wherein the second pump is disposed in the second fluidpathway disposed in fluid communication with, and interposed between,the heat rejecting heat exchanger and the refrigerant storage container.6. The refrigerant recovery device of claim 1, further comprising an oilseparator disposed in the first fluid pathway in fluid communicationwith, and interposed between, the pump and the heat rejecting heatexchanger.
 7. The refrigerant recovery device of claim 1, furthercomprising an oil separator disposed in the first fluid pathway.
 8. Therefrigerant recovery device of claim 1, further comprising a pressurerelief device disposed in fluid communication with the heat rejectingheat exchanger.
 9. The refrigerant recovery device of claim 1, whereinthe refrigerant containing device contains a refrigerant to be recoveredcomprising a refrigerant having a 100-year global warming potentialrelative to a carbon dioxide reference gas of less than or equal to2000.
 10. The refrigerant recovery device of claim 1, wherein the heatrejecting heat exchanger comprises a heat conducting coil disposed inthermal communication with a consumable heat sink.
 11. The refrigerantrecovery device of claim 1, further comprising a controller in operablecommunication with the pump and the plurality of valves and configuredto change an operating state of one or more valves of the plurality ofvalves to establish one of the first fluid pathway and the second fluidpathway based on one or more feedback conditions.
 12. The refrigerantrecovery device of claim 11, wherein the one or more feedback conditionscomprise at least one of a pressure of the refrigerant containingdevice, a pressure of the heat rejecting heat exchanger, a pressure ofthe refrigerant storage container, a pressure of the oil separator, atemperature of the refrigerant containing device, a temperature of theheat rejecting heat exchanger, a temperature of the refrigerant storagecontainer, a temperature of the oil separator, or an elapsed time. 13.The refrigerant recovery device of claim 1, wherein the establishment ofthe first fluid pathway is mutually exclusive with the establishment ofthe second fluid pathway.
 14. The refrigerant recovery device of claim1, further comprising a movable structure configured to hold one or moreof the fluid interface, the pump, the heat rejecting heat exchanger, therefrigerant storage container, or the plurality of valves.
 15. A methodof removing a refrigerant from a refrigerant containing devicecomprising: pumping the refrigerant along a first fluid pathway from therefrigerant containing device through a heat rejecting heat exchangerand into a refrigerant storage container until an initial pull-downthreshold condition is satisfied; cooling the refrigerant as it passesthrough the heat rejecting heat exchanger; and pumping the refrigerantalong a second fluid pathway from the heat rejecting heat exchanger tothe refrigerant storage container until a final pull-down thresholdcondition is satisfied.
 16. The method of claim 15, wherein the initialpull-down threshold condition comprises reaching one or more of apredetermined pressure condition within the refrigerant containingdevice, a predetermined temperature condition within the refrigerantcontaining device, a predetermined pressure condition within the heatrejecting heat exchanger, a predetermined temperature condition withinthe heat rejecting heat exchanger, a predetermined pressure conditionwithin the refrigerant storage container, a predetermined temperaturecondition within the refrigerant storage container, or a predeterminedinitial pull-down time duration.
 17. The method of claim 15, wherein thefinal pull-down threshold condition comprises reaching one or more of apredetermined pressure condition within the heat rejecting heatexchanger, a predetermined temperature condition within the heatrejecting heat exchanger, a predetermined pressure condition within therefrigerant storage container, a predetermined temperature conditionwithin the refrigerant storage container, or a predetermined secondpull-down time duration.
 18. The method of claim 15, further comprisingat least partially obstructing the second fluid pathway whilerefrigerant is pumped along the first fluid pathway; and at leastpartially obstructing the first fluid pathway while refrigerant ispumped along the second fluid pathway.
 19. The method of claim 15,further comprising pressurizing the heat rejecting heat exchanger whenthe refrigerant is pumped along the first fluid pathway anddepressurizing the heat rejecting heat exchanger when the refrigerant ispumped along the second fluid pathway.
 20. The method of claim 15,further comprising: providing a refrigerant removal device comprising apump, the heat rejecting heat exchanger and the refrigerant storagecontainer disposed in configurable fluid communication, wherein therefrigerant removal device is configurable between at least a firstconfiguration establishing the first fluid pathway and a secondconfiguration establishing the second fluid pathway; configuring therefrigerant removal device in the first configuration; fluidlyconnecting the refrigerant containing device to the refrigerant removaldevice; pumping the refrigerant with the pump along the first fluidpathway while at least partially obstructing the second fluid pathway,cooling the refrigerant in the heat rejecting heat exchanger before itenters the refrigerant storage container; receiving the refrigerant inthe refrigerant storage container; and pumping the refrigerant with thepump along the second fluid pathway while at least partially obstructingthe first fluid pathway.